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Abstract

Background

Physical activity, particularly walking, is greatly beneficial to health; yet a sizeable
proportion of older adults are insufficiently active. The importance of built environment
attributes for walking is known, but few studies of older adults have examined neighbourhood
destinations and none have investigated access to specific, objectively-measured commercial
destinations and walking.

Methods

We undertook a secondary analysis of data from the Western Australian state government’s
health surveillance survey for those aged 65–84 years and living in the Perth metropolitan
region from 2003–2009 (n = 2,918). Individual-level road network service areas were
generated at 400 m and 800 m distances, and the presence or absence of six commercial
destination types within the neighbourhood service areas identified (food retail,
general retail, medical care services, financial services, general services, and social
infrastructure). Adjusted logistic regression models examined access to and mix of
commercial destination types within neighbourhoods for associations with self-reported
walking behaviour.

Conclusions

The types of neighbourhood commercial destinations that encourage older adults to
walk appear to differ slightly from those reported for adult samples. Destinations
that facilitate more social interaction, for example eating at a restaurant or church
involvement, or provide opportunities for some incidental social contact, for example
visiting the pharmacy or hairdresser, were the strongest predictors for walking among
seniors in this study. This underscores the importance of planning neighbourhoods
with proximate access to social infrastructure, and highlights the need to create
residential environments that support activity across the life course.

Keywords:

Background

The health benefits of a physically active lifestyle are comprehensive and well documented.
Physical activity reduces the risk of cardiovascular disease, hypertension, stroke,
type 2 diabetes, osteoporosis, obesity, some cancers, anxiety, and depression
[1]. In addition, physical activity participation reduces risk of falls and fall-related
injuries, and prevents or delays functional and mobility limitations in older adults
(defined as ≥65 years of age in Australia)
[2]. Yet, older adults are among the least physically active. Participation in sufficient
amounts of physical activity to accrue health benefits, defined as at least 30 minutes
of moderate-intensity activity on most days of the week
[3], remains low around the world. In Western Australia, 52.5% of adults aged over 45
years are sufficiently active, and this further reduces to only 30.1% among those
aged ≥80 years
[4]. Using objective physical activity data obtained with accelerometers, Troiano and
colleagues reported just 2.4% of the U.S. population aged 60+ to be sufficiently active
[5]. With the population ageing, the importance of promoting and encouraging older adults
to be physically active will only grow in public health significance.

For older adults, one of the most popular forms of physical activity undertaken is
walking
[6]. It is highly accessible, low in cost, can be easily integrated into daily routines,
and often occurs on neighbourhood streets and in public areas within the neighbourhood
[7]. The importance of the neighbourhood environment in which people live and how it
impacts walking is consistent with social-ecological models of behaviour. Such frameworks
posit that multiple levels of interacting factors within a person’s surrounds will
influence their behaviour
[8,9]. In other words, individual factors (e.g., demographic characteristics), interpersonal
relationships (e.g., social networks and social support systems), physical environment
factors (e.g., built and natural environments), and public policy factors (e.g., laws
and regulations) work synergistically to influence walking. Thus, to increase population
physical activity patterns, attention must be given towards the implementation of
multi-level interventions
[10].

Researchers have shown neighbourhood walkability, a composite measure of residential
density, street connectivity, and land-use mix characteristics, to be related to walking
among older adults
[11-13]. But for research findings to be translated into policy and practice, more detailed
information is required, particularly in terms of specific types and mixes of neighbourhood
destinations that may be necessary to support walking. Only a handful of studies have
examined access to specific neighbourhood destinations (e.g., public transport, post
boxes, and convenience or grocery stores)
[14-17]. Yet, the types of neighbourhood destinations associated with walking may differ
across the life course. For example, access to schools may be important for children
and workplaces salient for employed adults, but have little relevance for retired,
older adults. Research involving older adults has considered the total number of neighbourhood
destinations
[18-20], but only one study among older women, which utilised self-reported environmental
data, has examined access to specific destinations within the neighbourhood and walking
[21]. The relationship between walking and the presence of a convenience, deli, or grocery
store within a 20 minute walk from home approached statistical significance, whereas
living within walking distance of a biking or walking trail, park, and department,
discount or hardware store were significantly related to daily pedometer steps among
older women
[21]. It is possible that access to neighbourhood destinations differentially relates
to walking according to gender. In addition, the aforementioned study used self-reported
perceptions to assess the presence of destinations
[21]. Others report poor concordance between self-report and objective environmental measures,
though environmental attributes measured using both types were independently associated
with walking, suggesting that the measures capture different dimensions of neighbourhood
environments
[22,23]. With scant evidence considering objective environmental measures, research is needed
to investigate whether the presence of specific, objectively-measured local destinations
relates to older adults’ walking. The aim of this study was to examine associations
between access to and mix of commercial destinations within the neighbourhood and
walking in a sample of older adults living in Perth, Western Australia.

Methods

This research involved a secondary cross-sectional analysis of data from the Health
and Wellbeing Surveillance System co-ordinated by the state government’s Department
of Health. Briefly, the surveillance system surveys people living in Western Australia
by Computer Assisted Telephone Interviews (CATI) to collect self-reported data on
health behaviours and levels and patterns of associated risk and protective factors
across the life course
[24]. Conducted monthly since 2002, 550 households are randomly selected from a stratified
sampling frame each month, with annual response rates ranging from approximately 80-84%.
Sample data are weighted to account for over-sampling and the probability of selection,
thus ensuring representativeness of the state’s population
[24]. For the present study, we utilised data collected between 2003 and 2009 for residents
of the Perth metropolitan region who were aged 65–84 years at the time data were gathered
(n = 2,918). Ethical approval was provided by the Department of Health Western Australia
Human Research Ethics Committee.

Self-reported walking

Within the surveillance system, physical activity behaviour is assessed using the
widely accepted Active Australia Survey
[25]. This tool has acceptable convergent validity for community-dwelling older adults
[26]. Based on public health recommendations for physical activity
[2,3], items on frequency and total duration of walking for recreation, exercise or to
get to or from places were used to compute two dichotomous dependent variables: prevalence
of weekly walking (none vs. some); and sufficient minutes of walking per week (insufficient
[i.e., <150 minutes] vs. sufficient [i.e., ≥150 minutes]).

Objective neighbourhood destinations

The full household address for each participant had previously been geocoded by the
Department of Health as part of the surveillance system
[24], enabling objective environmental data to be linked using a Geographic Information
System (GIS). Individual-level neighbourhood service areas were produced based on
400 m and 800 m road network distances from participants’ home address, distances
informed by the literature
[18,19,27,28].

Comprehensive data on neighbourhood destinations were purchased from Sensis Pty. Ltd.
– the data custodians of the Australian Yellow Pages — for three time points (2004,
2005, and 2007). This allowed us to match the most temporally relevant spatial data
to the surveillance data. In sum, Sensis data from 2004 were matched to participants
surveyed from February 2003 to June 2005, 2005 data matched to those surveyed from
July 2005 to December 2006, and 2007 data for the remaining participants. Individual
destinations were grouped into six mutually exclusive categories according to domain:
food retail (e.g., delicatessen, supermarket); general retail (e.g., newsagent, shopping
centre); medical care services (e.g., doctor, medical centre); financial services
(e.g., bank, post office); general services (e.g., hairdresser, pharmacy); and social
infrastructure (e.g., café or restaurant, church or place of worship).

Access to each commercial destination type was specified for both the 400 m and 800
m neighbourhood service areas. In addition, the number of commercial destination types
present within each service area was summed to examine the mix or diversity of accessible
commercial destinations within each participant’s neighbourhood.

To account for potential confounding effects, street connectivity was calculated as
the count of three (or more) intersections divided by the area (m2) of each participant’s service area. This was computed for both the 400 m and 800
m neighbourhood service areas, with values standardised as z scores across the sample.

Statistical analysis

Analyses were conducted using SAS v9.2. Logistic regression models examined the prevalence
of some walking and engagement in sufficient minutes of walking, and relationships
with access to and mix of commercial destination types within 400 m and 800 m neighbourhood
service areas. In addition, the moderating effect of sex was investigated by including
the cross-product term within the model, and then conducting stratified analyses to
interpret any significant interactions. All models progressively adjusted for demographic
covariates (i.e., age, sex, highest education level, marital status, self-rated health,
and use of assistive equipment) and street connectivity within the service area. P
values less than 0.05 were considered statistically significant.

Results

Demographic characteristics for the study sample (n = 2,918) are presented in Table
1. In summary, most participants were aged 65–74 years (61.8%), were female (55.9%),
and were married (62.0%). Approximately 12% of the sample rated their health as ‘excellent’,
while a similar proportion used assistive equipment to aid health conditions. Overall,
66.2% of participants reported engaging in some weekly walking. However, most of them
(69.2%) reported <150 minutes per week, with only 30.8% engaging in sufficient walking.

As seen in Table
2, the most common type of commercial destination accessible within 400 m of participants’
home was medical care services (27.2%). Approximately one half of the sample lived
within 800 m of food retail (50.0%) and general services (51.3%), while 58.0% had
access to social infrastructure within the 800 m neighbourhood service area. In terms
of the mix of destination types accessible within 400 m and 800 m neighbourhood service
areas, mean scores were 1.0 (SD = 1.5, range = 0-6) and 2.8 (SD = 2.1, range = 0-6)
respectively.

Table 2.Proportion of sample with access to commercial destinations within 400 m and 800 m
neighbourhood service areas

Table
3 presents the unadjusted and adjusted odds ratios examining access to and mix of commercial
destinations within 400 m and 800 m neighbourhood service areas associated with some
walking. After adjustment for demographic characteristics, access to general services
(i.e., hairdresser or pharmacy) within 400 m (OR = 1.33, 95% CI = 1.07–1.66, p = 0.011)
and 800 m (OR = 1.20, 95% CI = 1.02–1.42, p = 0.027) were both positively related
to participation in some walking. Also, older adults were 1.19 times more likely to
engage in some walking when social infrastructure, such as a café or restaurant, or
church or place of worship, were present within the 800 m neighbourhood service area
(95% CI = 1.01-1.05, p = 0.043). Street connectivity was significantly associated
with some walking within both 400 m (OR = 1.12, 95% CI = 1.02-1.22, p = 0.015) and
800 m (OR = 1.11, 95% CI = 1.02-1.22, p = 0.019) service areas. With further adjustment
for street connectivity, only access to general services within 400 m remained significantly
associated with some walking (OR = 1.29, 95% CI = 1.03-1.61, p = 0.027), though associations
for access to general services and social infrastructure within 800 m were still in
a positive direction.

Table 3.Odds ratios examining access to and mix of commercial destinations associated with
some walking

Unadjusted and adjusted odds ratios examining access to and mix of commercial destinations
within 400 m and 800 m neighbourhood service areas and associations with sufficient
walking are presented in Table
4. No significant differences were found for street connectivity within 400 m or 800
m services areas and sufficient walking. The only commercial destination type significantly
associated with sufficient walking was medical care services, which reduced the odds
of sufficient walking when accessible within 400 m (OR = 0.77, 95% CI = 0.63-0.93,
p = 0.008) and 800 m (OR = 0.83, 95% CI = 0.70-0.99, p = 0.044) respectively and adjusted
for both demographic characteristics and street connectivity. Sex did not significantly
moderate any of the associations examined (results not shown).

Discussion

We examined associations between the presence of objectively-measured access to specific
commercial destination types within the neighbourhood and older Australian’s walking,
and found some differences in the types of commercial destinations associated with
seniors’ walking compared with those generally reported among adults. This lends support
to the need for policy-makers and practitioners to plan or retrofit neighbourhood
environments that support physical activity across the life course.

Our findings suggest that access to destinations providing more opportunities for
social interaction – such as restaurants and religious institutions – and destinations
enabling some incidental social contact on a more regular basis for older people –
such as pharmacies and hairdressers – appear to be positively associated with walking
among older adults. This follows some findings in adult populations, where closer
proximity to restaurants and religious or cultural areas positively related to walking
for transport-related purposes
[16,17]. However, providing neighbourhood destinations where people can meet and engage with
others may have important implications for the ageing population beyond physical health
and walking. For example, access to proximate socially-based facilities has the potential
to increase levels of social engagement and participation in retired older adults,
who no longer have work-related social contact opportunities and who generally travel
shorter distances from home
[30,31]. Social activity is a key component of successful ageing
[32], and is consistently linked with health and well-being
[33-35]. This underscores the importance of planning neighbourhoods with proximate access
to social infrastructure, not only for physical activity and health, but also for
optimising the ageing process.

Retail destinations were found to be non-significantly related to walking in our sample.
This is somewhat surprising and contrasts previous findings among adults, in which
proximity to retail destinations such as local convenience stores, supermarkets or
grocery stores, and newsagents are consistently and positively associated with transportation
walking
[14-17]. It is possible that proximity to retail destinations is less important for seniors
compared with adults; however there are several other factors that warrant consideration.
The purpose of travelling to retail destinations is to shop and purchase goods, and
older adults may have less muscle strength to enable them in carrying their shopping
home
[1]. Furthermore, the additional weight associated with carrying shopping may reduce
self-efficacy, which is an important mediator between fear of falling and functional
ability
[36]. Issues of self-efficacy may also relate to the quality of walking infrastructure,
such as footpaths and the presence of benches or resting places along the route to
retail destinations. The supportiveness or quality of neighbourhood environments for
older adults’ walking has been previously reported
[37].

We found the presence of medical care services to be negatively associated with sufficient
walking, replicating the finding of Wang and Lee
[19]. There may be some possible explanations for this, for example the reduced likelihood
of walking may reflect unaccounted for self-selection bias. Seniors may purposefully
seek to live in neighbourhoods with proximate access to medical care services, and
planners and medical practitioners may intentionally locate medical care services
in neighbourhoods with higher proportions of older adults. Though older adults are
more likely to use such medical care services and to report them as being important
destinations to access within the neighbourhood
[38], others report that older adults have an increased propensity to carpool or be driven
by family members when traveling to medical appointments
[39]. It may be that even when medical care services are accessible within the neighbourhood,
it is not the type of destination in which someone would necessarily walk when physically
unwell and in need of medical care. Moreover, medical care services may occupy such
large land parcels that other destinations, which older adults may indeed walk to,
cannot also be located in the area. It is also important to note that the older adult
population is not homogenous, and the needs of the ‘young-old’ and ‘old-old’ may differ
greatly in terms of the importance of close proximity to medical care services and
whether or not they walk to this destination type. Future research should consider
self-selection effects and age moderation effects when examining commercial destinations
of importance across the life course.

When adjusting for the effects of street connectivity, we found access to destinations
within the 400 m neighbourhood service areas to remain significantly associated with
walking, however within the 800 m service areas, previously positive relationships
between walking and access to general services and social infrastructure were no longer
significant. It is worth noting that street connectivity and access to destinations
are related, as a more connected street network encompasses more possible routes along
the street network, increasing the area or size of service areas, and larger services
areas are more likely to have destinations present within them. Nonetheless, the findings
suggest that street connectivity may not impact the association between destinations
and shorter walks (i.e., within 400 m), as much as it does for longer walks (i.e.,
within 800 m). It may be that street connectivity plays a different sort of role in
influencing walking when destinations are located further away, and may mediate relationships
between walking and access to destinations within 800 m. Evidence supporting the role
of street connectivity on physical activity in older adults is mostly mixed, with
some reporting positive associations
[40-42], others reporting negative associations
[20,43,44], and still others reporting no relationship
[18,40,45]. This may be because the importance of street connectivity, and the direction of
its influence, may be dependent upon the environmental scale considered. However,
it is also possible that other attributes may be important to consider when examining
access to destinations within 800 m service areas. For example, perceptions of distance
and the directness of possible walking routes may contribute to the attenuating associations
at 800 m. Future research considering objective and perceived measures of the same
built environment attributes at the same environmental scale, and then across varying
environmental scales, would assist in attempts to further disentangle relationships.

Study limitations

The current study has several limitations to consider. While we attempted to categorise
commercial destinations by type or domain, it is possible that these require further
specification and understanding, based on the purpose and frequency for which older
adults visit such destinations. For example, fast-food outlets have been categorised
as food retail in previous studies
[46,47], but we chose to include it within the social infrastructure category based on findings
among older adults
[48]. It is also possible that food retail requires further specification in that supermarkets
or grocery stores are probably visited more often than other types of food retail
destinations. In addition, destinations that are frequently used by older adults (e.g.,
bank, post office, supermarket) generally had low proportions in this study, indicating
that our sample had poor access to commercial destination types overall.

Other limitations include the cross-sectional design, which limits causality, and
the influence of self-selection bias cannot be discounted. Also, utilising existing
data from a surveillance system was a limitation in that our behavioural outcome measures
were self-reported and assessed total, not purpose specific, walking. The influence
of neighbourhood environmental attributes on walking appears to differ according to
walking purpose, i.e., for recreational walking and transport walking
[49], and the need for measures that are context and behaviour specific has been previously
highlighted
[50]. This may explain why many commercial destination types within the neighbourhood
were not associated with walking in our study.

Conclusions

Commercial destinations within the neighbourhood that promote walking in an older
population appear to differ from those among adult samples. Destinations allowing
opportunities for more social interaction, be that more purposeful (e.g., visiting
a café or restaurant, church involvement), or incidental (e.g., visiting the hairdresser),
appeared to encourage seniors’ walking. Neighbourhood environments with access to
proximate social destinations may not only promote walking and physical activity,
but also help ensure older residents remain socially engaged with the local community.
In sum, our findings highlight the need to plan residential environments that are
supportive of all age groups in society.

Competing interests

The authors declare that they have no competing interests.

Authors’ contributions

AN contributed to study conception and design. GP conducted the analysis. AN, GP,
SF interpreted data and drafted the manuscript. PH contributed to study conception
and critically revised drafts. DS, BGC designed the overall study and critically revised
drafts. All authors read and approved the final manuscript.

Acknowledgements

This research was funded by a Western Australian Health Promotion Foundation (Healthway)
grant (#18922) and a Research Development Award from The University of Western Australia.
All authors were supported by an NHMRC Population Health Capacity Building Grant (#458668).
Sarah Foster was additionally supported by a Healthway Health Promotion Research Fellowship
(#21363) and Billie Giles-Corti by an NHMRC Principal Research Fellowship (#1004900).
The authors acknowledge Dr Sarah Joyce and the Data Linkage Unit from the Department
of Health WA for providing surveillance data.

Nelson M, Rejeski WJ, Blair S, Duncan P, Judge J, King AC, Macera CA, Castaneda-Sceppa C: Physical activity and public health in older adults: recommendation from the american
college of sports medicine and the american heart association.